Exam 2 Slideshow 6

Question 1

Inertia =

Mass =

Answer 1

Inertia = Resistance to motion

Mass = Measure of body’s linear intertia

Question 2

Kinetics =

Answer 2

cause of motion

Question 3

Centric forces cause =

Answer 3

linear (translational) motion only (Float Serve)

Question 4

Eccentric (off-center) forces =

Answer 4

always cause rotational motion
(sometimes linear motion, too) (Jump topspin serve)

Question 5

Eccentric Forces: Torque
(a.k.a. moment of force)

Answer 5

Torque is the turning or rotational
effect of an eccentric force

Units: Nm

Question 6

Torque at a given joint
is a measure of =

Answer 6

strength

Question 7

Net Torque

Answer 7

Torques acting around the same
axis may be summed

Question 8

Momentum Arm

Answer 8

The moment arm can change
based on the position of the
segment/object

Question 9

Center of Gravity

Answer 9

COG is location of axis of
rotation when airborne

Can move outside of body

Question 10

Four Properties of a Fluid

Answer 10

Pressure
Density
Specific Weight
Viscosity

Question 11

Types of Flow

Answer 11

Laminar
Turbulent

Question 12

Laminar

Answer 12

FLUID MOLECULES FLOWING
PARALLEL TO ONE ANOTHER
- “SMOOTH”
- “ORDERED”

Question 13

Turbulent

Answer 13

• FLUID MOLECULES MIX IN A
  RANDOM MANNER
• “CHAOTIC”
• “UNORDERED”

Question 14

BUOYANCY

Answer 14

• AN UPWARD FORCE
• A “FLUID REACTION FORCE”

Question 15

ARCHIMEDES PRINCIPLE

How does the free body diagram look?

Answer 15

THE BUOYANT FORCE IS EQUAL TO THE
WEIGHT OF THE FLUID DISPLACED BY THE BODY
*F B = V D y
* y = SPECIFIC WEIGHT OF FLUID

Buoyancy and weight arrows go in opposite directions

Question 16

BUOYANT FORCE in Fluid

Answer 16

• IF A BODY IS IMMERSED IN A FLUID IT WILL ALWAYS
  EXPERIENCE A BUOYANT FORCE EVEN IF IT IS NOT MOVING

Question 17

DYNAMIC FLUID FORCES

Answer 17

MOTION BETWEEN THE FLUID AND THE BODY OCCURS

Question 18

LIFT FORCE

Answer 18

• FORCE ACTING PERPENDICULAR TO FLUID FLOW (RELATIVE FLOW)
• 90 degrees TO MOTION
• “LIFTS” BODY

Question 19

DRAG FORCE

Answer 19

• FORCE ACTING IN DIRECTION OF FLUID FLOW (RELATIVE FLOW)
• OPPOSES MOTION
• SLOWS BODY

Question 20

RELATIVE VELOCITY =

Answer 20

VELOCITY OF BODY RELATIVE TO THE FLUID

VFLUID – VBODY

Question 21

Drag

Answer 21

• FORCE ACTING IN DIRECTION OF
  FLUID FLOW (RELATIVE FLOW)
• OPPOSES MOTION
• SLOWS BODY

Question 22

Types of Drag Forces

Answer 22

Surface

Form

Question 23

Types of Drag Forces

Surface

Answer 23

FORCE ACTING ON SURFACE OF BODY OR OBJECT (“SKIN FRICTION”)

Question 24

Types of Drag Forces

Form

Answer 24

FORCE CREATED BY PRESSURE DIFFERENCE BETWEEN FRONT AND BACK
SIDES OF A BODY IN RELATIVE MOTION

Question 25

Lift

Answer 25

• FORCE ACTING
  PERPENDICULAR(90O ) TO FLUID
  FLOW (RELATIVE FLOW)
• “LIFTS” BODY

Question 26

Bernoulli’s Principle

High velocity
corresponds with

Low velocity
corresponds to

Answer 26

High velocity
corresponds with
decreased pressure

Low velocity
corresponds to high
pressure

Question 27

MAGNUS EFFECT

Answer 27

• DEVIATION IN TRAJECTORY OF A SPINNING OBJECT TOWARD THE DIRECTION OF SPIN